Electric cut-out



Oct. 14. 1924. 1,511,369

M. J. SANDIN ELECTRIC CUT-OUT Filed June 17 1920 INVENTOR j ATTORNEYWITNESSES:

i 1G circuit interru v315 currents of Patented Oct. 14, 1924.

. UNITED STATES 1,511,369 PATENT OFFICE.

HOUSE ELECTRIC & VANIA.

MANUFACTURING COMPANY, A CORPORATION F PENNSYL- ELEcTaIc CUT-OUT.

Appneon mea :une i7, mo. serial m. ssasss.

To all whom zt may concern.'

Be it known that I, MAUnrrs J. SANDIN, ya citizen of the United States,and a resident of Vilkinsburg, in the county of Allel 6 gheny and Stateof Pennsylvania, have invented a new and useful Improvement in ElectricCut-Outs, of which the following 1s a specification..

My invention relates to automatic electric ters or cut-outs and it hasfor one of its o jects to prevent the unnecessary interruption of thecircuit in case the current onlytemporarily, exceeds a predeterminedvalue.

Another object of my invention is to provide a cut-out device of thecartridge type that may be emplo ed in connection with ordinarycartridge-glee terminal clips and that shall embody a readily-renewableactuating element of suchI form and relation to the cartridge as topreclude the substitution of make-slnft devices therefor.

A further object of my invention is to provide a cut-out device,embodying a heating coil, that shall havemeans for preventing damage tothe coil by overloads of excessive value or durationV and that shallembody thermal-responsive means for interrupting a circuitsimultaneously at a plurality o f series-related positions.

In certain electric circuits, it is desirable to protect the motor orother devices therein against sudden excessive overload currents and,also, against relatively slight overload excessive duration. The firstcondition is taken care of by fuses and automatic circuit interrupters.

It is desirable .to permit relatively small overloads, such as startingcurrents, to travf 0 erse thecircuit for-a relatively short period oftime'withont interrupting the circuit, as, otherwise, an unduenumber ofinterruptions mi ht occur. f

o this end, eut-'outs have been emplo ed which are responsive totemperature.y Iii a relatively light overload, not suflicient to ae-4tuate the automatic interrupters and other protective devices, issustained for 'any considerable time, the thermal-responsive cutout willinterrupt thecircuit.

racticing my invention, I provide a retilla le-cartridge cut-out deviceinfwhich a coaxially-aligned heating member, supporting a heating coil,projects into the carmember where they portion 9 of relatively ecarborundum and carbon,

tridge from one end ferrule thereof. A renewable thermal-responsiveelement, comprising two annular conducting members soldered together inconcentric relation, are mounted on the free end of the supporting areheld by a screw member projecting from the other end ferrule of thecasing. The outer conduct' member is adapted to engage contact membersprojecting into the cartridge from said other end ferrule. Alongitudmally biased sleeve member normally rests against the outerconducting member to move the latter in the direction of the axis of thecartridge to interrupt a circuit through the cartridge in response to apredetermined temperature t ereln.

Figure 1 of the accompanying drawings is l an enlarged longitudinalsectional view of a. cut-out device embodying my invention.

Fig.y 2 is a view, taken along the-line II-:II of Fig. l.

Fig. 3 isa view, similar to Fig. 1, partially in elevation and partiallyin section.'

Figs.'4 and 5 are'detail views of a ther. mal-responsive element shownin Figs. 1, 2 and 3.

Fig. 6 is a detail view of a supporting and spacing member shown in lig.1, and

F ig. 7 is a detail sectional view of a modified form ofthermal-responsive element embodying my invention.

A tubular insulating casing 1, preferabl constructed of fiber, isrovided, at one en with a fixed en d ferru e tached in any preferredmanner and, at its other end, with a removable ferrule 3, both 2 thatmaybe atof which lit inside the ends "of the casing 1 and are adaptedfor insertion inthe usual cartridge terminal clips (not shown).

A heating member 4, extending longitudinally in the casing 1, has ayhollow end portion 5 and a solid end portion 6 of different diameters,thus providing a shoulder 7 therebetween. The end portion 6 has aslightly tapered shoulder portion 8 and a threadedy small diameter. A

eating coil 10 embed d in suitable insulating material 11, such as acement constituted chlefiy of carborundum or of a mixture of is disposedin the hollow endvportion 5 of the heating member 4 and has one end 12soldered to the ferrule 2. The insulating material 11 is of suchlcharacteristics as to become a conductor at a predetermined temperatureto form a protective shunt path around the heating coil and to therebyprevent damage to the latter when it is subjected to excessive currentfor a certain period of time. The characteristics of the insulatingmaterial may be varied by changing the proportion of the ingredientsthereof, the proportion used being determined by the circuit conditions.The end 13 of the coil 10 extends into a recess 15 in the end portion 6and is connected to the member 4 by a body of solder 14. The end terrule2 and the hollow end portion 5l are provided with suitable insulatinglinings 16 and 16, such as asbestos and mica, re-

spectively. This provides good thermal and electrical insulation for theerrule 2 and electrical insulation that is a relatively good heatConductor for the portion 5.

A metal sleeve 17, having portions 18 and 19 of different diameters forembracing the end portion 5 of the heating member 4 and fitting againstthe inner walls of the casing 1, respectively, has an intermediateportion 20 provided with apertures 21 to reduce -the conduction of heatbetween the heating.

member 4 and the casing 1.

An insulating washer 22 covers the apertures 21 to prevent convection ofheat from one side to the other of the portion 20 of the sleeve 17 and,with insulating spacing washers 23 disposed between the washer 22 andthe inner end of the ferrule 2, electrically insulates the ferrule 2from the sleeve 17.

A transverse insulating barrier member or i washer 24 embraces the endportion 6 of the heating member 4 against the shoulder 7 and extends tothe inner surfaces of the casing 1. A heat-insulating collar or sleeve25 covers the greater portion of the end 6 of the heating member 4.

A thermal-responsive element 26 comprises two conducting members 27 and28 of substantially cup-shape, the member 27 having a central opening ofslightly larger diameter than the open-end perimeterr29 of the member 28to receive the latter. A relatively thin annular band or ring 30 offusible material, such as solder, normally holds the members 27 and 28together. The member 28 has a slightly sloping end portion 31lubstantially corresponding to the shoul- The end portion 6 is soproportioned as to lprovide a predetermined'time limit in which heat isconducted fi'oi'i'-"they heating coil 10 to the element 26 and also topermit the element and other parts to be contained in a casing ofsubstantially minimum size.

The end ferrule 3 is provided with an in- I terio'rly-projecting4'insulating member or post 32 secured thereto by a metal sleeve 33having 'edges 34 crimped `or bent intol relatively tight grippingengagement with the tending toward member 32. An interiorly-threaded camember 35 for engagement with the threa ed portion 9 of the heatingmember 4 is provided with a sleeve portion 36 having its edges 37 alsoin relatively tight gripping engagement with the member 32. An insulating sleeve member 38 normally surrounds the members 32 and 35 and isprovided with a rigidly secured annular ring4 or flange member 39between which and the closed end of the ferrule 3 a helicalcompressionspring 40 is disposed.

The member 33 is provided with elongated resilient arm portions 41disposed adjacent to the inner surface of the! ferrule 3 and eX- theinterior of the casing 1 that are provided, at their inner ends, withcontact portions 42 for engagement with the member .27 of the element26and a shoulder portion 43 for engagement with the flange 39 to limitthe outward travel of the sleeve 38 when the feri'ule 3 is detached fromthe casing 1. f

When it is desired to insert the element 26, the end ferrule 3, carryingthe members 32, 33, 35 and 38 and the spring 40, is turned to unscrewthe cap member 35 from the threaded portion 9 of the heating member 4.lThis presents substantially unobstructed, easy-V access to the threadedportion 9, since the latter is disposed relatively close to the end ofthe casing 1. When the ferrule 3 is removed', the unitary element 26,consisting of the 'members 27 and 28 and the fusible portion 30, may bereadily placed in position over the threaded portion9 against theshoulder 8. The dimension ofthe element 26', along its longitudinalaxis, is such as-to prevent its being reversely mounted in the casing.This dimension being greater than the length of the threaded portion 9,will prevent the mounting of the ferrule 3 if the element 26 isreversed.

In replacing the ferrule 3, the outer end of the sleeve 38 will be inadvance of the contact portions 42 and seat itself concentrically aboutthe member 28 against the transverse surface of the member 27.Furtherinward movement of the errule 3,to screw the cap member 35 inposition on the threaded end portion 9, compresses the'r spring 40 andplaces the element 26 under stress at its soldered portion. Whensufficient heat tofuse the material 30, in response to predeterminedcircuit conditions, traverses the heating member 4, the member 26 willbe released and moved quickly, by the sleeve 38 andthe sprin 40, alongthe portion 6 of the heating mem er 4, to a position against the barriermember 24.

When the members 27 and 28 separate, arcs will' be drawn between theouter edge of the member 27 and the Contact portions 42 and, also,between the inner edge of the member 27 and the outer` edge of the mem--ber 28. These arcs will be greatly lengthened as the member 27 is movedlongitudinally in the casing l, and the sleeve 38 will interpose aninsulating barrier, tending to prevent a sustained arc or to increasethe rupturing capacity, bet-Weenthe contact portions 42 and the member28. Further, the heating coil 10 is so helically wound andconcentrically/disposed about the longitudinal axis of the casing as toset netic iield, the collapse of which, on opening the circuit, assistsin quenching the arc drawn to the, member 27 when it is moved againstthe barrier member 24, the member 27 being thus moved into the magneticield of the coil 10.

W'hile a device constructed in accordance with my invention is adaptedfor insertion in the usual cartridge-fuse clips, it is, by itsconstruction, substantially. proof against the employment therein offuse Wire, or other subterfuges, of higher capacity or of differentoperating characteristics than those for which it is intended.

lt is to be understood that the element 26 may be of various othershapes and construction and, instead of comprising two separate memberssoldered together, it may consist of one piece having a weakened portion44, as illustrated in Fig. 7. Various other changes may be effected inmy device, Within the spirit and scope of my invention, as set forth inthe appended claims.

I claim as my invention:

1. A cut-out device comprising a thermalresponsive element constitutinga plurality h of sections of sheet material joined edge to edge andhaving one substantially continuous Surface and fusible means permittina portion of the area of said surface to be isplaced relative to theremainder of the element in response to a predetermined temperature andfor separating the said portion from the element.

2. A cut-out device comprising a casing, a supporting member disposedtherein, a thermal-responsive element disposed on the supporting member,an end ferrule for the casing, and a member on the ferrule projectinginto` the casing and having threaded engagement with the supportingmember to hold said element and the ferrule in position.

3. A cut-out device comprising a cylindrical member, a heating memberdisposed longitudinally therein, and an annular metal spacing andsupporting member between said members having cut-away portions toreduce the conduction of heat in-the spacing member.

4. A cut-out -device comprising a cylindrical member, a heating memberdisposed longitudinally therein, and an annular metal spacing andsupporting member between said members having cut-away portions toreduce the conduction of heat in the spacup a maging member, and aninsulating barrier memer covering said cut-away portions.

5. A cut-out device comprising a hollow heat-conducting membercontaining a heating element` a thermal-responsive conductive elementmounted thereon having a portion separable therefrom and heating meansdisposed therein.

(i. A cut-out device comprising a casing, a supporting member disposedlongitudinally therein, a transverse insulating barrier member embracingthe supporting member and extending to the Walls oi" the casing, athernial-responsive element mounted on the supporting member andprojecting transversely therefron, a Contact member engaging theelement,and a sleeve biased against the element and movable longitudinally overthe supporting member to a position against the barrier member toelongate an arc between the end of the supporting member and saidcontact member.

7. A cut-out device comprising relatively movable conducting members anda movable tubular insulating member for surrounding one of theconducting members and interposing an insulating barrier to elongate thearc between said members when the latter are actuated.

8. A cut-out device comprising an insulating casing, conducting endferrules therefor, a heat-conducting member having a threaded endportion supported longitudinally in the casing. a heating coil connectedbetween said ferrules, a thermal-responsive element av'ing an openingfor mounting the same over said threaded end portion, .a Contact memberengaging said element, a member projecting from one of said ferrules andhaving a threaded portion for engagement with said threaded end, and asleeve engaging the element and adapted to move longitudinally in thecasing.

9. A refillable cartridge cut-out device comprising an insulatingcasing, a removable end ferrule therefor, a heating member disposedlongitudinally in the casing and having an end portion disposed adjacentto said ferrule, an annular thermal-responsive element having separablecentral and rim portions supported on said end portion, a resilientcontact member connected to said ferrule for engagement with said rimportion, holdin means on said ferrule for engagement with said endportion, an insulating sleeve surroundin said holding means and biasedlongitudinally in the casing against said rim portion, a second ferruleat the other end of the casing, and heating means connected between saidsecond ferrule and said heating member.

10. A cut-out device comprising a thermal-responsive element, a heatingconductor therefor and means for insulating and shunting the samecomprising a body of maducting means,

terial that is an insulator and a conductor under diiferentpredetermined temperature conditions.

11.'A cut-out device comprising a thermal-responsive element, a heatingconductor therefor and means for insulating and shunting the samecomprising a body of material that is normally an insulator and that isa conductor at a predetermined relatively high temperature. l

12. A cut-out device comprising a plurality of relatively movablenon-fusing co-operating conducting means for interrupting a circuitsimultaneously at a plurality o series-related positions, one of thesaid con ductive means beingmaintained in conductive relation to theother by a fusible conductive material.

13. A cut-out device comprising a plurality of relatively movablenon-fusing conand thermal-responsive fusible means for holding saidconducting means vin co-operative circuit relationl and interruptin thecircuit to form a plurality of series-re ated arcs when thethermal-responsive means is actuated.

14. A thermal cut-out comprising a dis-- coidal thermal-responsiveelement consisting of a air of separable non-fusing conductive discsjoined at'their edges by fusible material and means exerting a shearingforce adjacent the pointofjoinder ,for sepa rating the conductive discswhen the fusible material is fused.

15. A thermal cut-out comprlsing a discoidal thermal-responsive elementconsisting of a central non-fusing conductive member and an annular-non-fusing member joined thereto by a fusible material, means forsupporting the central member and means exerting a shearing forceadjacentthe oint of jomder for separating the conductive discs when thefusible material is fused.

1.6. A thermal cut-out comprising a pairv f of tubular telescopinginsulating members,

a conductor extending through the inner tubular member, a thermal-resonsive element comprising two separab e portions joined by fusiblematerial having one portion secured to the said conductor and ada ted tobe surrounded by the outer tubu ar member, a conductor mountedexteriorly of the outer tubular member and engaging the free portion ofthe said element, and means for relatively moving the'tubulartelescopmembers for separating the. portions of the thermal-responsive'element when the fusible material is fused.

InY testimony whereof, Ihave hereunto subscribed my name 1920. i

y MAURITS J. sANDIN.

this 14th day of June,

